How does this medication work? What will it do for me?

Terbinafine belongs to the class of medications called antifungals. It is used to treatcertain types of fungal infections of the skin and nails.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

How should I use this medication?

The recommended adult dose is 250 mg once daily. If you have reduced liver or kidney function, your doctor may recommend a lower dose. The length of treatment depends on the condition being treated and the severity of the infection.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones given here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed. Use the medication for the prescribed length of time even if the infection clears up, to prevent it from coming back. If you miss a dose, take it as soon as you remember. If it is the following day before you remember your next dose, skip the missed dose and resume your usual dosing schedule. Do not take a double dose to make up for a missed one.If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Blood counts: This medication may decrease the number of neutrophils (a type of white blood cell that helps fight infection), red blood cells (which carry oxygen), and platelets (which help your blood to clot). Your doctor will do blood tests to monitor this. If you notice any signs of infection (e.g., fever, chills, or sore throat) or unusual bleeding or bruising, contact your doctor immediately.

Depression: Rarely, this medication has been reported to cause mood swings and symptoms of depression. If you have depression or a history of depression or anxiety, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. If you experience symptoms of depression such as poor concentration, changes in weight, changes in sleep, decreased interest in activities, or notice them in a family member who is taking this medication contact your doctor as soon as possible.

External use only: Terbinafine cream and spray are for external use only. Avoid contact with the eyes. Do not use the spray on the face. In case of accidental contact with the eyes, rinse eyes thoroughly with running water and consult a doctor if any symptoms persist. In case of inhalation, contact a doctor if any symptoms develop and persist. Topical forms of terbinafine are not effective for treating fungal infections of the nails.

Kidney function: The safety and effectiveness of using terbinafine have not been determined for people with decreased kidney function. The kidneys are partially responsible for removing terbinafine from the body. Decreased kidney function may cause terbinafine to build up in the body causing side effects. If you have decreased kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: Terbinafine tablets are not recommended for people with chronic (long-term) or active liver disease. Decreased liver function can cause terbinafine to build up in the body, causing side effects including further liver damage. Your doctor may order liver function tests before you start and while you are taking terbinafine tablets. During treatment with terbinafine, report to your doctor any signs or symptoms of liver problems including unusual fatigue, loss of appetite, yellowing of skin or eyes, abdominal pain, nausea and vomiting, dark urine, pale stools, or itching.

Lupus erythematosus: Occasionally, people taking terbinafine report a flare-up of systemic lupus erythematosus (SLE). If you have SLE, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Sensory disturbances: People taking terbinafine occasionally experience changes in how they sense things. Vision changes, difficulty hearing, a decreased sense of touch, change in the sense of taste or loss of smell have all been reported. If you notice changes while you are taking this medication, contact your doctor.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking terbinafine, it may affect your baby. Women taking terbinafine tablets should not breast-feed. If you are using the cream or spray, talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children.

What other drugs could interact with this medication?

There may be an interaction between terbinafine and any of the following:

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

stop taking one of the medications,

change one of the medications to another,

change how you are taking one or both of the medications, or

leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.